The present invention relates generally to a method and system for analyzing wooden structures with radar. More particularly, the invention relates to a method and system for detecting and characterizing anomalies in wooden utility poles.
The power-utility-system infrastructure alone in North America includes approximately 150,000,000 wooden pole structures. A similarly large number of wooden poles are additionally used by the telecommunications industry. Wood remains valuable as a material for constructing power and telecommunications poles because of its cost effectiveness and reasonable durability. Such poles are, nevertheless, subject to deterioration over time, not only from climatic effects, but also from biological and mechanical assaults. For example, biological deterioration may result from the activity of decay fungi, wood-boring insects, or birds. Woodpeckers have been known to bore vertical tunnels in wooden poles greater than twelve feet in length. Mechanical damage can result from such things as vehicular collisions or shotgun impacts. Consequently, each wooden pole in the system must be inspected periodically and a determination made whether to replace the pole based on the strength of the pole. Typically, poles are inspected on a 5-9 year cycle.
Various methods currently exist for evaluating pole strength, generally requiring direct physical contact with the pole. Such methods rely primarily on sampling techniques in which the strength of the pole is deduced from an assessment of its characteristics at the sampled points. Such sampling is typically performed in the region of the pole easily accessible by a technician, i.e. between about six feet above the ground to about two feet below the ground, so that only about 10% of the pole is even within the sampling region. Crossarms, which are positioned near the tops of the poles, are rarely examined for deterioration. Current methods also tend to include significant reliance on the qualitative assessment of the technician examining the pole. Individual visits to every pole to perform the inspection additionally result in substantial costs for maintaining the pole infrastructures.
There is accordingly room for improving the reliability of wooden-pole deterioration measurements by examining substantially the entirety of the structures and automating the evaluation of their strength. In addition, the cost for assessing the structures can be reduced by using a system that eliminates the need to have each pole visited individually.